Enhancement of the performance of flexible lead-free nanogenerators by doping in BaTiO3 nanoparticles

Barium Titanate (BaTiO 3) lead-free ceramic has recently gained the attention for the fabrication of nanogenerators. Herein, lead-free piezoceramics (Ba, Ca) (Zr, Ti)O 3 was synthesized using the sol-gel method. In order to improve the material properties, Ca 2+ and Zr 4+ were introduced into the BaTiO 3 crystal network to replace Ba 2+ and Ti 4+ , respectively. Subsequently, three flexible nanocomposites were chemically fabricated by mixing polyvinylidene fluoride‐co‐hexafluoropropylene (PVDF-HFP) with the commercial BT, the synthesized BZT and BCZT, using the solution‐casting technique. The microstructure and morphology were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and (SEM). This study illustrates that the combination of both addition Ca 2+ and Zr 4+ in barium titanate is promising for forming the electroactive β-phase in the nanocomposite. The XRD and FTIR confirmed the formation of the polar β-phase, enhancing piezoelectric properties. The electrical conductivity of the nanocomposite increased with doping in both sites. A maximum output voltage (∼1.8 V) and power (∼1.9 μW) was achieved for composite including BCZT particles. Besides, different sizes and concentrations of BCZT/PVDF-HFP based nanogenerators were constructed. The optimal performance was with nanogenerators of size 2 cm × 2.5 cm and 10 wt % of BCZT powders. Biomechanical foot-tapping achieved a maximum output voltage of 4.55 V, which was high enough to become a potential candidate for a self powered device in future applications. • Lead-free nanoparticles successfully synthesized using sol-gel method. • Doping Zr 4+ and Ca 2+ within BT particle boost the piezoelectric performance. • BCZT/PVDF-HFP revealed high output power of 1.9 μW at a low resistance load of 800 KΩ. • The dielectric property increases with doping in both sites from Ɛ’ = 20 F m −1 to Ɛ’ = 65.14 F m −1 . • BCZT based NG favorites the potential use of the nanogenerator for biomechanical energy harvesting up to 4.55 V by foot tapping.